JOHANNESBURG (miningweekly.com) – ASX-listed Lithium Australia has developed a new hydrometallurgical process for the recovery of lithium from spodumene.
Dubbing it the “holy grail” of lithium processing, the company said that the Sileach process was a low-energy, low-cost and low temperature method, that did not require roasting.
Independent laboratory tests of the Sileach process achieved lithium extractions, from alpha spodumene, of up to 92% in four hours.
“This potentially changes the cost curve for the production of lithium chemicals…hardrock lithium [was previously faced] with energy intensive processes dictating what can and cannot be economically processed,” MD Adrian Griffin noted.
He added that prior to the process, only high-grade spodumene concentrates were viable under such conditions. The low-grade materials, including mica, had been “destined for waste dumps”.
The Sileach process also had the potential to release the value from stranded lithium silicate deposits – those deposits quarantined by sub-economic grades – while transforming low-grade spodumene occurrences into viable ore as lower projected operating costs makes it less sensitive to feed grade.
This resulted in lower cut-off grades for resource calculations, expansion of existing resources without the requirement for further drilling, and greater recovery of metal inventories.
As the lithium was precipitated from solution in the Sileach process, all impurities in lithium silicate feed were rejected during the production of lithium chemicals.
Griffin added that while there was “no shortage” of lithium deposits or concentrating plants, there was a a significant shortage of lithium carbonate and hydroxide plants. “Lithium Australia is focused on filling that gap with its leading edge environment-friendly processing technologies.”